The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
The operating temperature of a typical automatic transmission in a motor vehicle is affected by various factors including, but not limited to, the operating loads and conditions placed on the transmission as well as environmental conditions. For example, an automatic transmission having a torque converter operating in converter mode (i.e., torque transfer occurs through the transmission fluid in the torque converter) increases the temperature of the transmission fluid. Additionally, operating under heavy acceleration or steep grades can also increase the temperature of the transmission.
Typically, a transmission heat exchanger is used to cool the transmission by transferring the transmission fluid heat to an engine coolant system. Therefore, the transmission fluid temperature is affected by the engine coolant temperature, the engine cooling system's volume, and the engine cooling system's ability to reduce additional transmission heat load. While heat exchangers are effective, there is room in the art for a method of controlling a transmission in order to reduce the temperature of the transmission fluid beyond the capabilities of the transmission heat exchanger and engine coolant system without requiring additional components.